feat: implement CreateMessageBatchAsync method

src/AnthropicClient/Models/MessageBatchResponse.cs

@@ -0,0 +1,98 @@
+using System.Text.Json.Serialization;
+
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents a response to a batch of messages.
+/// </summary>
+public class MessageBatchResponse
+{
+  /// <summary>
+  /// Gets the identifier of the batch.
+  /// </summary>
+  public string Id { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets the type of the batch.
+  /// </summary>
+  public string Type { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets the processing status of the batch.
+  /// </summary>
+  [JsonPropertyName("processing_status")]
+  public string ProcessingStatus { get; init; } = string.Empty;
+
+  /// <summary>
+  /// Gets the counts of requests in the batch.
+  /// </summary>
+  [JsonPropertyName("request_counts")]
+  public MessageBatchRequestCounts RequestCounts { get; init; } = new MessageBatchRequestCounts();
+
+  /// <summary>
+  /// Gets the date and time when the batch ended.
+  /// </summary>
+  [JsonPropertyName("ended_at")]
+  public DateTimeOffset EndedAt { get; init; }
+
+  /// <summary>
+  /// Gets the date and time when the batch was created.
+  /// </summary>
+  [JsonPropertyName("created_at")]
+  public DateTimeOffset CreatedAt { get; init; }
+
+  /// <summary>
+  /// Gets the date and time when the batch expires.
+  /// </summary>
+  [JsonPropertyName("expires_at")]
+  public DateTimeOffset ExpiresAt { get; init; }
+
+  /// <summary>
+  /// Gets the date and time when the batch was archived.
+  /// </summary>
+  [JsonPropertyName("archived_at")]
+  public DateTimeOffset ArchivedAt { get; init; }
+
+  /// <summary>
+  /// Gets the date and time when the batch cancellation was initiated.
+  /// </summary>
+  [JsonPropertyName("cancel_initiated_at")]
+  public DateTimeOffset CancelInitiatedAt { get; init; }
+
+  /// <summary>
+  /// Gets the URL to the results of the batch.
+  /// </summary>
+  [JsonPropertyName("results_url")]
+  public string ResultsUrl { get; init; } = string.Empty;
+}
+
+/// <summary>
+/// Represents the counts of requests in a batch of messages.
+/// </summary>
+public class MessageBatchRequestCounts
+{
+  /// <summary>
+  /// Gets the number of requests in the batch that are processing.
+  /// </summary>
+  public int Processing { get; init; }
+
+  /// <summary>
+  /// Gets the number of requests in the batch that succeeded.
+  /// </summary>
+  public int Succeeded { get; init; }
+
+  /// <summary>
+  /// Gets the number of requests in the batch that errored.
+  /// </summary>
+  public int Errored { get; init; }
+
+  /// <summary>
+  /// Gets the number of requests in the batch that were cancelled.
+  /// </summary>
+  public int Canceled { get; init; }
+
+  /// <summary>
+  /// Gets the number of requests in the batch that expired.
+  /// </summary>
+  public int Expired { get; init; }
+}